Wood Fly Ash Research Articles

Accelerating acidogenic fermentation of sewage sludge with ash addition

A statistically designed range of tests was used in order to map the impact of time, temperature and pH on the acidogenic fermentation of sewage sludge with the addition of wood fly ash. The main factors investigated were temperature (35, 55 and 65 °C), pH (7, 8 and 8.5) and retention time (1, 2 and 4 days). The initial pH was adjusted by adding ash. Up to about a third of the volatile solids could be solubilized in less than two days retention time. Higher temperatures (55 and 65 °C) and adjusted pH (7 and 8) favored hydrolysis whereas fermentation producing organic acids was faster at lower temperatures (35 °C). Sludge hydrolysis occurred fast at 55 and 65 °C, reaching a solubilized total organic carbon (TOC) concentration of 3.84 g TOC L−1 after one day. Thermophilic conditions (55 and 65 °C) resulted in a lower volatile fatty acids (VFA) concentration compared to mesophilic conditions (35 °C). At 35 °C, the highest VFA concentration was measured after 4 days and initial pH 7 (10.0 ± 0.2 g COD L−1). This study showed the potential of using a waste stream to increase and hasten the hydrolysis of particulate organics, resulting in higher TOC solubilized in 2 days, while promoting a higher VFA production presented as g COD L−1.

Alkaline Wood Ash, Turbulence, and Traps with Excess of Sulfuric Acid Do Not Strip Completely the Ammonia off an Agro-waste Digestate

The present study combined two nutrient management strategies to improve the marketability of a waste-derived fertilizer: (a) isolation of ammoniacal nitrogen and (b) preparation of a bulk soil amendment. The wood fly ash with low content of pollutants was added to an agrowaste anaerobic digestate as alkaline stabilizer, which promoted the volatilization of ammonia and adsorption processes, and as nutrient supplement. The 39.71 ± 1.44 g blend was incubated for 60 hours at 20°C and 100 rpm in a closed chamber (250-mL Schott Duran® bottle) with a 5.21 ± 0.10 mL sulfuric acid trap of 10 different concentrations (0.11, 0.21, 0.32, 0.43, 0.54, 0.64, 0.75, 0.86, 0.96, and 1.07 mol/L). For analytical purposes, the sulfuric acid, water-soluble, and water-insoluble fractions of the blend were isolated after the incubation. The 1.07 mol/L sulfuric acid solution contained 23.69 ± 5.72 % more of ammonical nitrogen than the 0.11 mol/L solutions. However, in all cases the amount of nitrogen in the H2SO4 compartment was lower than the one in the water-soluble and water-insoluble fractions. Only the 15.52 ± 2.13 % of the nitrogen accounted after the incubation was found in the H2SO4 trap. The bottleneck of the NH3 stripping process was the rate of mass transfer at the interface between the blended fertilizer and the headspace of the closed chamber. The organic phosphorus was more susceptible to be adsorbed during the alkaline treatment with non-intrusive acidification than the nitrogen and carbon. Activation of the ash as adsorbent before mixing with the digestate should improve the properties of the blend as slow release fertilizer, since more nutrients would end in the water-insoluble fraction.

Wood Fly Ash Stabilized Road Base Layers with High Recycled Asphalt Pavement Content

Wood fly ash stabilised road base layers with high recycled asphalt pavements content was studied both at the laboratory and in-situ. The original recipe was chosen based on an actual stabilised pavement base layer design with cement CEM II/B-T 42.5R but optimised using wood fly ash. The existing road base layer from gravel was mixed with dolomite aggregate and recycled asphalt pavement, adding cement and wood fly ash at different proportions. The mixture was compacted at optimal water content according to the Standard Proctor test and further conditioned. Resistance to freezing and thawing of hydraulically bound mixtures was checked after 28 days of conditioning. Even 50 cycles of freezing and thawing were used. Test results indicated wood fly ash as an effective alternative to the typically used cement for road base stabilisation, including recycled asphalt pavement material. Three hydraulically bound mixtures were chosen for test sections in the pilot project. The project includes five different sections with three different hydraulic binder recipes. The performance of each section was evaluated.

Influence of wood pretreatment and fly ash particle size on the performance of geopolymer wood composite

In search for greener building materials, geopolymer wood composites (GWC) were produced through alkali activation of fly ash, using pine and eucalypt wood particles. The study examined the influence of grinding fly ash, wood species and hot water treatment of wood particles on the physical properties and specific compressive strength of GWC before and after 200 cycles of soaking and drying. Ash-grinding affected particle size distribution, as the hot water pretreatment of the wood affected its extractives. The particle size analysis showed that grinding decreased the mean particle size of raw ash by 55% and played a major role in the composite’s properties, as lower densities and specific strength with high water absorption were recorded for GWC from raw ash than from ground ash. The ash-grinding step doubled the specific strength of the composites before the aging test. A decrease in specific strength (15–32%) was observed for all composites after the soaking and drying cycles. Hot water washing of the wood resulted in a 47% and 67% reduction in the extractive content of the pine and eucalypt particles, respectively. An improvement of 27% and 3% was noted in specific strength values respectively for GWC with treated pine and eucalypt particles. In general, lower specific strength was recorded for pine-based composites than eucalypt ones, due to the fast impregnation and high water absorption from the mixture by pine particles. It was revealed that hot water treatment of wood improves GWC properties less compared to wood species or fly ash particle size.

Suitability and characteristics of combustion residues from renewable power plants for subbase aggregate materials, in Thailand

Physico-chemical properties and the environmental impacts were studied relative to the leaching of rubber fly ash and bottom ash. The pozzolanic properties of fly ash and bottom ash were confirmed by the chemical composition, including silicon oxides, calcium oxides, and aluminum oxides. The geo-technical characteristics of rubber wood fly ash and bottom ash, i.e., modified compaction, plasticity, and the soaked California Bearing Ratio, were evaluated to assess the feasibility of fly ash or bottom ash mixed with lateritic soil as aggregate materials for the subbase in road construction in order to optimize the replacement of lateritic soil by fly ash or bottom ash. The leachates from rubber fly ash and bottom ash did not exceed standard thresholds. The measured characteristics of fly ash or bottom ash mixed with lateritic soil were in good alignment with the effective engineering thresholds. Recommendations were developed for safe reuse of byproducts from rubber renewable power plant in subbase road construction.

Waste Wood Fly Ash Treatment in Switzerland: Effects of Co-Processing with Fly Ash from Municipal Solid Waste on Cr(VI) Reduction and Heavy Metal Recovery

In Switzerland, waste wood fly ash (WWFA) must be treated before deposition on landfills due to its high pollutant load (Cr(VI) and heavy metals). Acid fly ash leaching, the process used for heavy metal recovery from municipal solid waste incineration fly ash (MSWIFA), represents a possible treatment for heavy metal depletion and Cr(VI) reduction in WWFA. The co-processing of WWFA with MSWIFA during acid fly ash leaching was investigated in laboratory- and industrial-scale experiments with different setups. Of interest were the effects on heavy metal recovery efficiency, the successful outcome of Cr(VI) reduction and consumption of neutralizing chemicals (HCl, H2O2). Detailed chemical and mineralogical characterization of two WWFA types and MSWIFA showed that MSWIFA has higher concentrations in potentially harmful elements than WWFA. However, both WWFA types showed high concentrations in Pb and Cr(VI), and therefore need treatment prior to deposition. Depending on the waste wood proportion and quality, WWFA showed chemical and mineralogical differences that affect leaching behavior. In all experimental setups, successful Cr(VI) reduction was achieved. However, WWFA showed higher consumption of HCl and H2O2, the latter resulting in a particularly negative effect on the recovery of Pb and Cu. Thus, co-processing of smaller WWFA portions could be expedient in order to diminish the negative effects of Pb and Cu recovery.

Evaluating Biomass Ash Properties as Influenced by Feedstock and Thermal Conversion Technology towards Cement Clinker Production with a Lower Carbon Footprint

Purpose: This study evaluates the potential of biomass ash as raw clinker material and the influence of biomass feedstock and thermal conversion technology on biomass ash properties. Methods: A set of criteria for biomass feedstock and ash properties (i.e. CaO/SiO2 ratio and burnability) are established. A large dataset was collected and the best combination of biomass feedstock and conversion technology regarding the desired ash quality was identified. Results: Wood biomass has the highest potential to provide the right CaO/SiO2 ratio which is needed to form clinker minerals. Bark content and exogenous Si inclusion in wood biomass have a large influence on the CaO/SiO2 ratio. Paper sludge is composed of Ca, Si and Al and can potentially serve as a source of cement elements. Wood fly ash from pulverized fuel combustion can substitute a considerable amount of raw clinker materials due to its similar burnability. The replacement ratio is determined by the content of adverse elements in the ash (i.e. MgO2 and P2O5). Conclusion: Using biomass ash to lower the CO2 emission from clinker production depends on the joint effort of bioenergy producers, by providing higher quality biomass ash, and cement makers, by adapting the kiln operation to enable a high level of raw material replacement by biomass ash.The presented evaluation of the ash production chain, from biomass selection through combustion technology and ash management, provides new insights and recommendations for both stakeholders to facilitate this sustainable development.Graphic

Alkali activation of different type of ash as a production of combustion process

Presented study deals with the final structure and radiological properties of different fly-ash based geopolymers. Lignite fly-ash (lignite Kolubara ? Serbia) and wood fly ash were obtained in combustion process together with commercial fly-ash. Synthesis of the geopolymers was conducted by mixing fly-ash, sodium silicate solution, NaOH and water. The samples were strengthened 60 ?C for 48 hours after staying at room temperature in covering mold for 24 hours. The X-ray diffraction, Fourier transform infrared and SAM measurements were conducted on the samples after 28 days of geopolymerization process. The X-ray diffraction measurements of lignite fly-ash samples show anhydrite as the main constituent, while wood fly-ash samples consist of calcite, albite and gypsum minerals. Besides determination of physicochemical properties, the aim of this study was radiological characterization of lignite fly-ash, wood fly-ash and the obtained geopolymer products. Activity concentration of 40K and radionuclides from the 238U and 232Th decay series, in ash samples and fly-ash based geopolymers, were determined by means of gamma-ray spectrometry, and the absorbed dose rate, D, and the annual effective dose rate, E, were calculated in accordance with the UNSCEAR 2000 report.

Ion availabilities in two forest soils amended with alkaline-treated biosolids, agricultural lime, and wood fly ash over a 10-week period

Two forest soil B-horizons were amended with alkaline-treated biosolids (ATB), powdered agricultural lime, and wood fly ash under controlled conditions to compare initial ion availabilities over a 10-week period. ATB was most effective in supplying available Ca2+but least effective in supplying available Mg2+, for which lime was most effective. Availability of K+and SO42–-S was greatest in fly ash amended soils because of high K and S loading rates and the high electrical conductivity of this amendment. Mineral N (NO3–-N + NH4+-N) availability increased in ATB amended soils, stayed the same in lime amended soils, and decreased in fly ash amended soils. Availability of PO43–-P was low in all soils but slightly enhanced in ATB amended soils. Fluxes of Cu2+, Pb2+, Zn2+, and Mn2+in amended soils generally decreased over time in association with increased soil pH. Fluxes of Cd2+were not affected by any treatment. Results suggest that ATB is equally as effective as or more effective than lime and fly ash at immediately supplying Ca2+, but less effective at supplying Mg2+because of low inputs and cation competition. This suggests that ATB amendments could be an alternative means of quickly adding available Ca2+to Ca-depleted forest soils as long as potential impacts on other nutrient base cations are considered.

Co-digestion of sewage sludge and wood fly ash

ABSTRACT This study uses a new approach for the recycling of plant nutrients by co-digesting sewage sludge with fly ash from a wood combustion. Sewage sludge and fly ash both are enriched with nutrients of the wastewater resp. wood, which makes these products an enhanced source for recycled fertilizers. The effects of the ash addition to the anaerobic digestion are studied in several lab scale experiments including effects on the gas production and microbial activity. Following that, the fertilizing qualities of the digestate are evaluated by plant growth experiments. The results show that the fertilizing qualities of the digested sludge were improved by the ash addition. Next to this, gas production results show that the methane production was not affected by the ash addition, while the total gas release was reduced. The sulphur addition by the ash stimulated sulphate reducing bacteria. The sulphate reducing bacteria did not markedly inhibit the methanogens.

Potensi Limbah Arang Kayu Alaban (Vitex pubescens Bahl), Abu Dasar dan Abu Terbang Batubara Sebagai Bahan Briket

Characterization of wood waste from halaban wood, bottom ash, and coal fly ash has been done includes tests of water content, ash content, calorific value, and composition as well as morphology. One of the factors that influences the characteristics is the powder size. Therefore, this research uses 250 mesh sieve (smaller powder size) to make briquettes. From the test results, the average moisture content was 4.22% for halaban wood charcoal, 1.64% for bottom ash and 0.91% for fly ash. Average ash content of 41.93% for halaban wood charcoal, 82.03% for bottom ash and 89.69% for fly ash. Average Calorie Value of 6833.1 cal/g for halaban wood charcoal, 389.5 cal/g for bottom ash and for coal fly ash with calorie value of 0. From the SEM-EDX analysis results, there was no C mean of 76.69% In halaban wood charcoal, the average ash percentage of C was 41.87% and the average percentage of C was 16.17% in coal fly ash. The results of tests carried out are expected to be waste wood charcoal, basic ash and fly ash can be used as a mixture in the manufacture of briquettes.

Mineralogy and Origin of Aerosol From an Arc Basaltic Eruption: Case Study of Tolbachik Volcano, Kamchatka

AbstractIntense emission of volcanic aerosol accompanied the 2012–2013 basaltic effusive eruption of Tolbachik volcano, Kamchatka. The aerosols sampled contain sulfuric acid droplets, glassy particles, and 70 mineral phases. All aerosol particles may be classified by their origin. The fragmentation aerosol includes magma fragments: silicate glass clasts, silicate microspheres, and small phenocrysts (olivine, pyroxene, and magnetite). The alteration aerosol comprises particles of quenched silicate melt covered with secondary minerals (fluorides, sulfates, and oxides/hydroxides of rock‐forming elements) and fragments of altered rocks composed solely of secondary minerals. The condensation aerosol dominated the mass during the later stages of the eruption when the explosive activity had ceased, and was characterized by the greatest variety of particle compositions. Na‐K sulfate and Fe (III) oxide comprised more than 95% of the solid fraction of the condensation aerosol. The remaining 5% was represented by native elements (Au, Ag‐Pt alloy, and Pt); sulfides of Fe, Cu, Ag, and Re; oxides and hydroxides of Al, Fe, Cu, Zn, Mo, W, Ta, and Zr; halides of Al, Mg, Na, K, Ca, Cd, Pb, Ag, and Tl; and sulfates of Na, K, Pb, Ca, and Ba; the only silicate was As‐bearing orthoclase. Droplets of H2SO4 formed the liquid phase of the condensation aerosol. Some of the aerosol components, such as magnetite spherules or phosphate‐carbonate‐fluorite association, likely had a nonvolcanic origin (country rocks and wood fly ash). The volcanic aerosols and their contained minerals, discharged at Tolbachik and elsewhere, result in a physical and chemical effect on the environment in the region of such volcanoes.

Comparative analysis of milling time on the particle sizes of coal fly ash and wood fly ash using Otsu Method for thresholding

South Africa remains one of the countries with an abundance of coal fly ash (CFA) emerging from her abundant coal deposit. Despite the hazardous and environmental unfriendliness of fly ash, so many benefits can be derived therein. With new policies of waste-to-wealth, the country seeks ways by which this resource could be of value addition. However, CFA in its raw form often requires further milling operation to enhance suitability for the intended use. This study investigated the effect of milling time on the particle size of CFA and wood fly ash (WFA) using image segmentation. Both CFA and WFA received at micro-sized particles were washed with distilled water to remove impurities and dried in the oven at 80°C for 48 hours then sieved using 75µm size. Microstructural images of both CFA and WFA milled at varying times (t = 0, 20, 40, 60 minutes) were morphologically and physiochemically analysed using scanning electron microscope (SEM), X-ray diffraction (XRD), Energy Dispersive X-ray (EDX), and X-Ray Fluorescence (XRF). SEM images of CFA and WFA were segmented using Otsu thresholding technique and average particle sizes were estimated. CFA contains a higher composition of Al2O3 (30.93%) and SiO2 (51.43%) compared to WFA, which has 10.70% and 46.31% respectively. However, WFA contains more of Fe2O3 (17.28%) than CFA (2.29%). The number of particle size increased with increases in milling time while the particle area decreased with an increase in milling time. At a 95% confidence interval, there exists a significant difference between results obtained at different milling time. Also, a significant difference exists between the mean particle diameters of the two ash sources.

A factorial experimental analysis of using wood fly ash as an alkaline activator along with coal fly ash for production of geopolymer-cementitious hybrids

Alkaline activated materials such as geopolymers and cementitious materials derived from pozzolanic reactions offer several advantages over the currently widely used Portland cement, especially in terms of environmental sustainability and physiochemical properties. However due to the need of an alkaline activator, such as NaOH or KOH, which result in high production cost and requires skilled personnel, they have not been deeply explored and put to use. Here in this study, wood fly ash, a by product of wood combustion is used as an alternative source of alkaline activator for producing such alkaline activated materials along with coal fly ash, where the resulting geopolymer–cementitious hybrid (GCH) was characterized physico-chemically through electron microscopy, BET, FTIR, XRF & XRD. However, the leaching of heavy metals from the wood fly ash could potentially pose an environmental concern. Therefore, the focus of this study is to reduce the leachability factor of wood fly ash involved in the alkaline activated process and to understand the effects of various factors (i.e. water-to-ash ratio (w/a), method of curing, type of alkaline activator and ash sieving) on the leaching process, through factorial experimental analysis. The leaching patterns of various elements such as Pb, Zn, Cr, As. Hg, Se were studied along with the contributing factors and results showed that the dominant factor was the type of alkaline activator (i.e. Wood Fly Ash versus Na2SiO3). By comparing the leaching data to Denmark’s leaching criteria, the best performing GCH sample was found to be 0.3DI_p_s (0.3 represents the w/a ratio, “p” denotes that samples were precured and “s” denotes sieving).

Influence of carbonaceous agrowastes nanoparticles on physical and Mechanical properties of friction stir processed AA7075-T651 metal matrix composites

Friction Stir Processing (FSP) is a mode of surface enhancement used to improve the properties and the surface quality of the fabricated samples. The main focus of this research was to make a comparative performance assessment using economical and eco-friendly carbonaceous agro-wastes nanoparticle as reinforcement in AA7075-T651 during FSP and to determine the surface roughness and the tensile strength of the produced samples. Nanoparticles of Wood fly ash (WFA), coconut shell ash (CSA), coal fly ash (CFA), palm kernel shell ash (PKSA) and cow bone ash (CBA) were developed. The processing parameters used on the FSP machine were rotational speed of 1500 rpm, 20 mm min−1 processing speed, 3° tilt angle, and 0.3 mm plunge depth. The physical and the mechanical properties of the fabricated samples were studied. Results revealed that metal matrix composites (MMC) reinforced with WFA-NPs has the best surface integrity with the least Ra of 1.60 μm, followed by AA7075-T651/CBA-NPs with Ra value of 2.81 μm while unreinforced but processed base metal (UBM)- AA7075-T651 was the roughest with Ra value of 11.61 μm. It was further observed that UBM produced the highest ultimate tensile strength (UTS), Rm with a value of 620.9 MPa, and this also produced the highest yield strength at 0.1%, 0.2% and 0.5% off strain given the following values 599.1, 572.9 and 588.5 MPa respectively. Amongst the fabricated MMC, the one reinforced with carbonaceous CSA-NPs produced the highest UTS, Rm with 379.9 MPa while there was tie values in UTS, Rm for WFA-NPs and CFA-NPs which was 367.8 MPa and AA7075-T61/CBA-NPs gave the least value of UTS, Rm with a value 298.1 MPa. Most of the fractured surface areas of the nanocomposites are dominated by the dimples-induced transgranular agreeing with the remarkable interfacial bonding with the aluminium matrix composites.

The effect of peat and wood fly ash on the porosity of mortar

Fluidized bed combustion fly ash (FBCFA), notably different from regular (coal) fly ash, is a promising industrial side stream to be used as a supplementary cementitious material (SCM). Peat and wood are important sources of biomass for energy production in Nordic countries and generate formidable amounts of un-used ash yearly. Two FBCFAs from the co-combustion of peat and wood, fly ash from coal combustion, and limestone filler were used to replace 10 wt%, 20 wt%, and 40 wt% of cement in mortar specimens. The compressive strength, porosity, water absorption, water vapor permeability, and drying shrinkage of the mortars were measured and compared. It was found that in almost all properties FBCFAs outperformed un-reactive limestone filler. Compared to coal fly ash, FBCFAs produced mortars with comparable compressive strength although with higher porosity, water absorption, and water vapor permeability.

Granulation of fly ash and biochar with organic lake sediments – A way to sustainable utilization of waste from bioenergy production

The main waste generated during the thermochemical processes of biomass burning used for bioenergy production in cogeneration plants are ash and biochar which can be used as fertilizers in forestry and agriculture. However, several difficulties are attributed to possibilities of practical exploitation of ash and biochar due to the transporting, handling and mode of application. Granulation of energy generation waste has been shown in some circumstances as a cost-effective and environmentally friendly method. Production of granules (pellets) from wood ash and biochar leads to improved recycling and logistics of waste as well as helps to control and avoid undesirable environmental effects such as leaching of nutrient excess.The aim of this study was to prepare granules from wood fly ash and biochar mixed with organic-rich freshwater lake sediments (sapropel) used as a natural binder and a source of organic matter for enrichment of derived granules to be applicable as a soil improver. Characterization of raw materials and derived granules included range of physical and chemical analysis. Applied granulation technology involved homogenization of components following by extrusion and drum granulation, and the process was developed for prospective production of soil improvers. It was estimated that the most optimal mass ratio of raw materials applicable for the process of granulation is 67:100 (fly ash to sapropel) and 30:100 (biochar to sapropel) resulting in production of granules 3–8 mm in diameter. Among the characteristic parameters of granules apparent density, bulk density, compressive strength, total element content and element content by fractions was assessed.

Comparative Study Of The Variability In The Compositions And The Effect Of Milling Time On Coal Fly Ash And Wood Fly Ash Nanoparticles

Abstract Industrial and domestic fly ashes (FA) also known as coal fly ash (CFA) and wood fly ash (WFA) respectively has been causing environmental menaces but in recent times they are gaining potential applications in various industries varying from Construction, processing, activated carbon, filler and reinforcement, agriculture to water purifications, to mention but a few due to its availability and low cost. There is every need to place these two fly ashes and weigh their compositions. In this study, the chemical and elemental compositions of both coal fly ash and wood fly ash are compared. The physiochemical and Morphological Characteristics of the milled and unmilled nano fly ashes were determined using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF) analyses. The milling times were taken at 0, 20, 40 and 60 mins and 0 min taken when sieved with 75µm size ASTM standard before milling. The crystal phases detected by the XRD in WFA are rhombohedral, hexagonal, cubic and tetragonal while that of CFA are hexagonal, orthorhombic, rhombohedral and anorthic. XRD analysis shown that the most dominant crystalline in wood fly ash were calcite (CaC03), quartz (SiO2), Sylvite (KCl), Lime (CaO), maghemite-Q (γ-Fe2O3), nitratetine (Na(NO3)) and magnetite (Fe3O4) phases; while in coal fly ash were Quartz (SiO2), Mullite (Al2.32Si0.68O4.84), Sillimanite (Al2(SiO4)O, Calcite high (CaCO3), Hematite (Fe2O3), Microcline (KAlSi3O8). The particles size got increased from 75µm to average diameter of 200nm. Morphological characteristics revealed that the surface of nano obtained shows that wood fly ash nanoparticles (WFA-NPs) has more irregular shape, rough and uneven compared to coal fly ash nanoparticles (CFA-NPs). As revealed by EDX the elemental composition that are present in Wood fly ash nanoparticles are Ca, K, Mg, Si, Al and Fe while that of coal fly ash nanoparticles are Si, Al, Ca, Fe, Ti and Mg. The overall effects of the grinding process showed that there are tremendous reductions in both the particle and crystallite size of CFA-NPs and WFA-NPs as well as great improvement in the metallurgical and mechanical properties of the two samples with respect to milling time when compared to unmilled samples.

Characterization of coal bio ash from wood pellets and low-alkali coal fly ash and use as partial cement replacement in mortar

Coal is increasingly replaced by biomass at the power plants. This results in new types of fly ashes, e.g. coal bio ash (CBA), where low-alkali coal fly ash (CFA) is injected to the boiler furnace during incineration of wood pellets to hinder corrosion and maintain the necessary thermal efficiency of the fuel. An assessment of the properties of this new type of ash is important for the utilization of this resource. This study reports an investigation of the filler behaviour and pozzolanic activity of CBA, when used as a partial cement replacement. Traditional CFA was used for comparison and CBA was shown to be a more favourable substitute compared to CFA. This study has shown, that by injecting CFA into the boiler furnace, wood fly ash is transformed from being a waste by-product, into a usable resource in concrete production.

Use of wood dust fly ash from an industrial pulverized fuel facility for rendering

Wood dust II fly ash, which was generated after boiler retrofit (implementation of low-NOx burners combined with over-fire air), apparently is an enhanced quality for rendering. This is attributed to the mineral phases formed, an increase in the amount of free lime, and performance test results. After accelerated aging tests, the wood dust II fly ash showed no visible occurrence of cracks or detachment of the render base coat from the substrate. Tensile strength values met the applicable limit requirement of 8 MPa. The results contribute to a sustainable ash management for wood fly ash from pulverized fuel facilities.